Re: std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment

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From	Pablo Halpern <phalpern@halpernwightsoftware.com>
Newsgroups	comp.std.c++
Subject	Re: std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment
Date	Thu, 1 Dec 2011 14:02:08 -0800 (PST)
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This defect has been submitted as issue #2103 in the active issues
list.  Thanks for writing it up.
-Pablo

On Nov 8, 2:32 pm, Ai Azuma<ai.az...@gmail.com> wrote:

> ===== beginning of the defect report =====
>
> Affected section of the standard:
> 20.6.9 [default.allocator]
>
> Description of the problem:
> `std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment::value'
> is specified as `false', according to (20.6.9) and (20.6.8.1).
> However, according to (23.2.1), this specification leads to
> the unneeded requirements
> (MoveInsertable and MoveAssignable of the value type)
> on the move assignment operator of containers
> with the default allocator.
>
> Proposed resolution:
> Either of the following two changes;
>
> (1)adding the nested typedef like
> `typedef std::true_type propagate_on_container_move_assignment;'
> in the definition of std::allocator class template,
>
> (2)adding the explicit partial specialization of
> `std::allocator_traits' class template for `std::allocator'
> class template, in which `propagate_on_container_move_assignment'
> nested typedef is specified as `std::true_type'.
>
> ===== end of the defect report =====
>
> Thank you.
>
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std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment Ai Azuma<ai.azuma@gmail.com> - 2011-11-02 11:16 -0700
  Re: std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment Pablo Halpern <phalpern@halpernwightsoftware.com> - 2011-11-03 17:10 -0700
    Re: std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment Ai Azuma<ai.azuma@gmail.com> - 2011-11-08 11:32 -0800
      Re: std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment Pablo Halpern <phalpern@halpernwightsoftware.com> - 2011-12-01 14:02 -0800

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